Expand Chapter

expand-chapter

You are running the expand-chapter skill. The chapter exists. This is the mandatory grounding pass the pipeline runs on every chapter — or a second pass because the critique (or the author) pointed at a concrete unmet need. Never a length fix: word counts are not measured here. Your job is not generic texture or dwelling — under this book's windowpane style, lingering for its own sake is a defect. The pass adds only these six kinds of insert, and only where the chapter shows the need:

1. The world, unfolded more slowly. A spot where the chapter uses a world element — a craft step, a rule of the magic, an institution, a custom — but rushes past it, so the reader is told rather than shown. Slow it down: one paragraph where the POV works the element and the reader watches the mechanism operate. Felt, not lectured; show it working, never explain the system behind it (the iceberg stays under the surface).
2. A visualization passage. A scene happening in a space the reader cannot draw — no scale, no layout, no light, no sense of what stands between the character and the door. Build the stage per style.md ("Build the stage"): establish the space anchored to the POV's body, so every action after it happens somewhere the reader can stand.
3. The bill (cost made visible). A spot where the page spends something — magic, physical effort, a favor, a social transgression — and moves on without showing the price. Insert the paragraph where the cost is felt: the hands that shake, the neighbour who no longer returns the look, the material that will not be replaced. Limitations are more interesting than powers; a spend with no bill is a rule quietly broken.
4. Deliberation on the page. A decision the chapter already contains, taken cold — the POV acts without the reader seeing the weighing. Insert the deliberation before the hinge, in the POV's own vocabulary: options, fears, the calculus. This is what keeps transparent prose warm. The hinge itself stays sharp and fast.
5. Re-orientation after a jump. A time or place cut that disorients: one short paragraph re-anchoring how long has passed, where we are, what changed in the gap. The temporal cousin of building the stage.
6. A secondary in three dimensions. A named secondary functioning as a prop: one specific beat — a gesture, a worn object, a contradiction — that makes them a person. At most one such insert per chapter, or the cast becomes a catalogue.

If a spot needs none of these, it gets nothing. A chapter that is already grounded, costed, and reasoned takes zero inserts, whatever its word count. Precedence: the beat sheet outranks every need test — a gap the outline marks as deferred or reserved is a seed, not a need; the test does not fire.

Hard rules

• Do not invent new plot beats. If the chapter has 4 plot beats, it still has 4 after expansion. Plot is decided in plan/outline.md.
• Do not contradict canon. If you need a fact that isn't there, flag it — don't make it up silently.
• Do not pad with filler. "She walked to the door. She opened the door. She stepped through." is failure. Expansion means deeper attention, not more sentences.
• Match the voice already on the page. Read the chapter first. Your additions should be indistinguishable from the existing prose. If the POV voice is declared spare (short sentences, little rumination, no big metaphors — see setup.md), expand with concrete texture and sensory detail, not interior monologue. Lyrical, ruminative padding is voice drift, not depth. Prefer the hand, the object, the labor over the character's thoughts about them.
• No word counting — the range in setup.md is a planning objective, not a check. Generated length is deliberately never measured back to the model (a visible count breeds compensation). Do not count the chapter's words before, during, or after the pass: every insert is justified by a need test or not at all. Stop when the needs are met. Better a lean chapter than a padded one.
• Do not break seed work. Existing planted/echoed seeds must stay exactly where they are. If you move a seed line, you risk breaking the echo or payoff chain.
• Spanish unless setup says otherwise.

Steps

1. Rebuild the context and read the chapter

python3 .claude/skills/write-chapter/scripts/build_context.py \
    --series-slug <slug> \
    --book-number <N> \
    --chapter <M> --phase expand

--phase expand builds a lighter bundle: a grounding pass adds no plot and reveals nothing, so it drops series context, the shadow slice, plan neighbors/arcs, the story-so-far summaries and the seam. It keeps what a grounding pass needs — setup, decisions, canon, the seed envelope (so inserts don't break seed lines), this chapter's beat sheet, style + voice, the dwelling checklist, and the voice spine last (insertions are exactly where the tics creep back in). Read both the bundle (notes/_context-chMM.md) and the chapter (chapters/MM.md).

2. Identify where the need shows

One read, one verdict. The tests fire on a first attentive read or not at all — do not re-read hunting for candidates; a need you must hunt for is not a need (it is the compliance reflex inventing work).

Write the candidate list before any prose. At most 6 lines, each: the exact quoted line where the need shows + which test + a one-line insert plan. A candidate that cannot quote its line is invented — drop it. Then write only the strongest survivors (3 inserts max, as ever); listing is not committing, and an empty list is a valid verdict — report zero inserts and stop.

The need tests — one per insert kind:

• World-rush test (→ 1): a sentence invokes a world element (craft, magic rule, institution, custom) the reader has never watched operate — a noun doing a system's work ("pagó el diezmo del color", "templó el hilo"). First time only: an element already unfolded in an earlier chapter is NOT a candidate again (trust the reader).
• Blur test (→ 2): the reader could not draw the space — scale, layout, light, what is underfoot, what stands between the POV and the exit — AND the scene uses the space (movement, distance, hiding, work). A scene that never uses its space needs no stage.
• Unpaid-bill test (→ 3): the scene spends magic, effort, a favor, or a transgression and moves on with no visible price.
• Cold-decision test (→ 4): a choice that matters (it changes the POV's situation) is taken with the weighing unseen. Trivial choices stay cold — deliberating everything is drift.
• Lost-reader test (→ 5): after a time/place cut, a first-time reader wouldn't know how long passed, where we are, and what changed.
• Prop test (→ 6): a named secondary is doing plot work with zero specific humanity on the page (max one per chapter, never during a hinge).

Constraints on candidates:

• Hinges stay sharp. Do not expand inside a decision, conflict, or revelation beat; ground before the hinge so the hinge can move fast.
• Transitions almost never qualify.

3. Choose techniques from dwelling-techniques.md

Read the techniques reference and pick the ones that serve the insert's job — techniques are means, the insert kinds are the end:

• For a world-unfolding paragraph, the natural fits are texture of labor (the hands, the resistance of the material, the small failures — the mechanism seen through work) and sensory anchoring (the element known by smell, sound, weight, not by name).
• For a stage-building passage, use the "Build the stage" rules in style.md directly: establish before moving, anchor geometry to the body, concrete over generic, re-anchor when the space changes. The room remembered (one object with a history placed in the space) can double as furniture and character.
• For a cost paragraph, keep it in the body and the world (sensory anchoring again): the price is a sensation, an object consumed, a changed reaction from someone — never the narrator announcing "it had cost him".
• For a deliberation paragraph, interior in motion is the tool: the weighing happens during an action, in the POV's vocabulary, and ends in the choice the chapter already makes.
• A re-orientation or secondary beat is short and plain — no technique needed beyond one concrete anchor.
• Time held still is seasoning, not a basis for an insert on its own — under the windowpane style an insert must ground, unfold, cost, or reason, not merely linger.

4. Apply expansion in-place

Use the Edit tool to insert new prose into the chapter file. Each insertion should:

• Be sized to its job: 60-150 words for a re-orientation or a secondary beat; 150-400 words of continuous prose for an unfolding, stage, cost, or deliberation passage. Never a list of beats.
• Sit at a spot that failed a need test in step 2, inside a scene the chapter already has.
• Begin with a sensory anchor (smell, sound, touch, taste).
• Carry at least one subtext layer — what the POV feels but doesn't say.
• Read invisibly between its markers: the prose itself should feel as if it was always there (the markers below are a temporary scaffold, not part of the prose).

Acceptable to insert at multiple points, but 3 insertions max per expansion pass. More than that and the chapter loses shape.

4b. Mark each expanded zone (temporary repo standard)

Standard while this repo is early: every inserted zone is wrapped in visible text markers so the author can read the chapter (including on Kindle) and tell original prose from added prose, and compare options. These markers stay in the file for now; they will be stripped in a later cleanup pass once the workflow is trusted.

Wrap each insertion with numbered visible markers on their own lines, blank line above and below:

▼▼▼ INICIO EXPAND N (prosa AÑADIDA — no original) ▼▼▼

<inserted prose>

▲▲▲ FIN EXPAND N ▲▲▲

• The number is the expand PASS (this skill invocation), not the zone. Before adding anything, scan the chapter for existing EXPAND markers:
  • No EXPAND markers found → this is pass 1: mark every zone you add in this invocation as EXPAND 1.
  • EXPAND 1 markers already present → this is pass 2: mark every zone you add in this invocation as EXPAND 2.
  • All zones added in the same invocation share the same number, however many they are. This way the author sees exactly what each call contributed and can compare passes. Full control.
• Use the language of the prose (Spanish by default).
• Plain text markers only — not HTML comments — so they survive the EPUB/Kindle export and are visible when reading.
• Cap: at most 2 expand passes per chapter. Do not invoke the skill a third time on the same chapter.

5. Second pass — only on demand, never from length

There is no verification step and no word count. A second pass (pass 2 — numbering and the 2-pass hard cap per 4b) happens only when the critique names a need test that fired with no insert, or the author asks for one. Never re-invoke the skill on your own initiative, and never count words to decide anything. If your one attentive read left you suspecting the outline planned too few texture beats for this chapter, flag that to the user as a plan observation — do not fix it with inserts.

6. Report

• Number of inserts, by need-test type (zero is a valid outcome).
• Which scenes you expanded (one line each).
• Which dwelling techniques you used (named, from the reference).
• Anything you noticed that should be flagged: missing canon facts, weak subtext, brittle transitions.

What this skill does NOT do

• Does not add new plot beats, characters, or settings.
• Does not change the chapter's POV, tense, or voice.
• Does not modify seeds, shadow, or plan files.
• Does not update canon (that's update-canon).